These pads were initially expanded with DNPT. The documentation of this industry is somewhat sparse.
Also, with time the DNPT was replaced by activated forms of ADCA like Celogen 754 and Cellmic Cap W.
The blowing agents covered were AIBN, DAB and DNPT. The process consisted of the following: a precure mold is filled completely and heated under pressure to 149 [degrees] C (300 [degrees] F) for 20 minutes.